The latter rain is given to the Church and it becomes an example to Israel of what God can do with people. It gives them hope. The Church will have a lukewarm reputation in the world but God will do wonderful things in the body of Christ before the Church is transformed into His bride.
"All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness," - 2 Timothy 3:16 ESV
God gave promises to Israel and the Church is not Israel or an extension of Israel. The Church is a beautiful foreign bride that God has taken to Himself and called His own. God has grafted the Church into His kingdom.
"Then I heard what seemed to be the voice of a great multitude, like the roar of many waters and like the sound of mighty peals of thunder, crying out, "Hallelujah! For the Lord our God the Almighty reigns. Let us rejoice and exult and give him the glory, for the marriage of the Lamb has come, and his Bride has made herself ready; it was granted her to clothe herself with fine linen, bright and pure' - for the fine linen is the righteous deeds of the saints." - Revelation 19:6-8 ESV
This spring rain will prepare the Church and move the corporate structure from 'the body' into 'the bride.' It will be a last pre-marriage preparation. A marriage that will be taking place in Heaven during the relatively calm first half of the time when craziness is about to break out in mass on the Earth.
When Moses took a foreign bride (See Numbers 12:1) it provoked his siblings to jealously and this latter rain revival will serve the same purpose. God does it out of love but He also will use the political backlash caused by His choice to convert Israel to Himself.
"So I ask, did they stumble in order that they might fall? By no means! Rather through their trespass salvation has come to the Gentiles, so as to make Israel jealous." - Romans 11:11 ESV
"The LORD answered and said to his people, 'Behold, I am sending to you grain, wine, and oil, and you will be satisfied; and I will no more make you a reproach among the nations... Be glad, O children of Zion, and rejoice in the LORD your God, for he has given the early rain for your vindication; he has poured down for you abundant rain, the early and the latter rain, as before. The threshing floors shall be full of grain; the vats shall overflow with wine and oil. I will restore to you the years that the swarming locust has eaten, the hopper, the destroyer, and the cutter, my great army, which I sent among you. You shall eat in plenty and be satisfied, and praise the name of the LORD your God, who has dealt wondrously with you. And my people shall never again be put to shame. You shall know that I am in the midst of Israel, and that I am the LORD your God and there is none else. And my people shall never again be put to shame. And it shall come to pass afterward, that I will pour out my Spirit on all flesh; your sons and your daughters shall prophesy, your old men shall dream dreams, and your young men shall see visions. Even on the male and female servants in those days I will pour out my Spirit. And I will show wonders in the heavens and on the earth, blood and fire and columns of smoke. The sun shall be turned to darkness, and the moon to blood, before the great and awesome day of the LORD comes. And it shall come to pass that everyone who calls on the name of the LORD shall be saved. For in Mount Zion and in Jerusalem there shall be those who escape, as the LORD has said, and among the survivors shall be those whom the LORD calls.' " - Joel 2:19, 23-32 ESV
Israel will be provoked to jealousy saying, 'How come they knew God and we don't? Remember what happened with the vilified Christian's before they vanished? Maybe God will save us also?'
God will send the latter rain on us to ripen His crop and then He will send rain to them in the midst of great trouble. Young people will be converted in the midst of Israel and those young people will be witnesses during that dark time.
"After this I saw four angels standing at the four corners of the earth, holding back the four winds of the earth, that no wind might blow on earth or sea or against any tree. Then I saw another angel ascending from the rising of the sun, with the seal of the living God, and he called with a loud voice to the four angels who had been given power to harm earth and sea, saying, 'Do not harm the earth or the sea or the trees, until we have sealed the servants of our God on their foreheads.' And I heard the number of the sealed, 144,000, sealed from every tribe of the sons of Israel:" - Revelation 7:1-4 ESV
God has the angels stand waiting and holding back while those witnesses are being converted. These are the young who will 'see visions' as the old men 'dream dreams.' Israel's conversion will happen in part because of the Church's last days revival. The bright light of the grace message will shine in the memories of those surviving daily calamity surrounded by lies and propaganda.
"Then I looked, and behold, on Mount Zion stood the Lamb, and with him 144,000 who had his name and his Father's name written on their foreheads. And I heard a voice from heaven like the roar of many waters and like the sound of loud thunder. The voice I heard was like the sound of harpists playing on their harps, and they were singing a new song before the throne and before the four living creatures and before the elders. No one could learn that song except the 144,000 who had been redeemed from the earth. It is these who have not defiled themselves with women, for they are virgins. It is these who follow the Lamb wherever he goes. These have been redeemed from mankind as firstfruits for God and the Lamb, and in their mouth no lie was found, for they are blameless." - Revelation 14:1-5 ESV
They will sing a new song no one else can sing because they were saved from what no one else has gone through. We sing our 'grace song' and they will have their glorious song.
God will use the Church to send grain, wine and oil to Israel and then God will redeem them in a like manner in a dramatic accelerated way similar to how He once delivered them from Egypt.
(FYI. If you want a good resource that goes into end times events in depth check out 'Things to Come' by Dwight Pentecost)
In a way our lives are a microcosm of all these things. Each of us living through different tragedies and experiencing different triumphs. Some of us live relatively controversy free lives and others seem to have trouble swirling around them all the time (or for extended seasons.) The love God has for us and our response to it has an impact on those around us. Perhaps it has a larger impact then we realize.
We can have a visible relationship with God that provokes people who don't have it to jealousy. Peace that passes understand by is available to us.
"I, the LORD, am its keeper; every moment I water it. Lest anyone punish it, I keep it night and day;" - Isaiah 27:3 ESV
As individuals we can live in constant hydration knowing that God will do what He does inside us and more for His Church publicly some day soon.